Affiliation: Department of Physiology, Kyung Hee University School of Medicine, Seoul, Korea.

ABSTRACTBrain-derived neurotrophic factor (BDNF) and its receptors tyrosine kinase B (trkB), and cyclic adenosine monophosphate response element binding protein (CREB) have been suggested as the neurobiological risk factors causing depressive disorder. Serotonin (5-hydroxytryptamine, 5-HT) plays an important role in the pathogenesis of depression. We in-vestigated the effect of treadmill exercise on social interaction in relation with BDNF and 5-HT expressions following stress in rats. Stress was induced by applying inescapable 0.2 mA electric foot shock to the rats for 7 days. The rats in the exercise groups were forced to run on a motorized treadmill for 30 min once a day for 4 weeks. Social interaction test and western blot for BDNF, TrkB, pCREB, and 5-HT1A in the hippocampus were performed. The results indicate that the spend time with unfamiliar partner was decreased by stress, in contrast, treadmill exercise increased the spending time in the stress-induced rats. Expressions of BDNF, TrkB, and pCREB were decreased by stress, in contrast, treadmill exercise enhanced expressions of BDNF, TrkB, and pCREB in the stress-induced rats. In addition, 5-HT1A receptor expression was de-creased by stress, in contrast, treadmill exercise enhanced 5-HT1A expression in the stress-induced rats. In the present study, treadmill exercise alleviated stress-induced social interaction impairment through enhancing hippocampal plasticity and serotonergic function in the hippocampus. These effects of treadmill exercise are achieved through 5-HT1A receptor activation.

f3-jer-11-4-192: Effect of treadmill exercise on pCREB expression in the hippocampus. (A) Control group, (B) control exercise group, (C) stress-induced group, (D) stress- induced and exercise group. The data are presented as the mean±standard error of the mean (SEM). *represents P<0.05 compared to the control group. #represents P<0.05 compared to the stress-induced group.

Mentions:
pCREB expression is presented Fig. 3. When the level of pCREB in the control group was set at 1.00, the level of pCREB was 0.96 ±0.04 in the control and exercise group, 0.66±0.03 in the stress-induced group, and 0.85±0.03 in the stress-induced and exercise group. Expression of pCREB in the hippocampus was decreased by induction of stress (P<0.05). In contrast, treadmill exercise enhanced pCREB expression in the stress-induced rats (P<0.05).

f3-jer-11-4-192: Effect of treadmill exercise on pCREB expression in the hippocampus. (A) Control group, (B) control exercise group, (C) stress-induced group, (D) stress- induced and exercise group. The data are presented as the mean±standard error of the mean (SEM). *represents P<0.05 compared to the control group. #represents P<0.05 compared to the stress-induced group.

Mentions:
pCREB expression is presented Fig. 3. When the level of pCREB in the control group was set at 1.00, the level of pCREB was 0.96 ±0.04 in the control and exercise group, 0.66±0.03 in the stress-induced group, and 0.85±0.03 in the stress-induced and exercise group. Expression of pCREB in the hippocampus was decreased by induction of stress (P<0.05). In contrast, treadmill exercise enhanced pCREB expression in the stress-induced rats (P<0.05).

Bottom Line:
Expressions of BDNF, TrkB, and pCREB were decreased by stress, in contrast, treadmill exercise enhanced expressions of BDNF, TrkB, and pCREB in the stress-induced rats.In the present study, treadmill exercise alleviated stress-induced social interaction impairment through enhancing hippocampal plasticity and serotonergic function in the hippocampus.These effects of treadmill exercise are achieved through 5-HT1A receptor activation.

Affiliation:
Department of Physiology, Kyung Hee University School of Medicine, Seoul, Korea.

ABSTRACTBrain-derived neurotrophic factor (BDNF) and its receptors tyrosine kinase B (trkB), and cyclic adenosine monophosphate response element binding protein (CREB) have been suggested as the neurobiological risk factors causing depressive disorder. Serotonin (5-hydroxytryptamine, 5-HT) plays an important role in the pathogenesis of depression. We in-vestigated the effect of treadmill exercise on social interaction in relation with BDNF and 5-HT expressions following stress in rats. Stress was induced by applying inescapable 0.2 mA electric foot shock to the rats for 7 days. The rats in the exercise groups were forced to run on a motorized treadmill for 30 min once a day for 4 weeks. Social interaction test and western blot for BDNF, TrkB, pCREB, and 5-HT1A in the hippocampus were performed. The results indicate that the spend time with unfamiliar partner was decreased by stress, in contrast, treadmill exercise increased the spending time in the stress-induced rats. Expressions of BDNF, TrkB, and pCREB were decreased by stress, in contrast, treadmill exercise enhanced expressions of BDNF, TrkB, and pCREB in the stress-induced rats. In addition, 5-HT1A receptor expression was de-creased by stress, in contrast, treadmill exercise enhanced 5-HT1A expression in the stress-induced rats. In the present study, treadmill exercise alleviated stress-induced social interaction impairment through enhancing hippocampal plasticity and serotonergic function in the hippocampus. These effects of treadmill exercise are achieved through 5-HT1A receptor activation.